Natural history of phenotype markers in patients with bronchial asthma (a decade’s observation)

Abstract

Volatility of certain bronchial asthma (BA) phenotype markers is not enough investigated during maturation of pediatric patients. Material and methods. One hundred thirty-one patients with non-severe BA were included; by the age on inclusion date subgroups of “Children” (62 patients aged 6 to 11 years) and “Adolescents” (69 patients aged 12–17 years) were allocated. Every 6 months patients were examined, fulfi   d asthma control questionnaires, performed spirometry with salbutamol test, provided hematology results with absolute eosinophil count and height and weight data. Exacerbation and hospitalization numbers, BA severity and controller treatment step were considered. Acquired data were archived; patients’ management was driven by real clinical practice algorithms.Results. Ninety-three patients included (71%) completed at least decade observation. Adolescents and young adults had body mass index higher than 90th percentile by age more often than younger children; some patients had normalized their body mass during observation. BMI and ACT results had moderate reverse correlation (r=–0.64). Eosinophil counts more than 300 cells per microliter conserved longer in older patients: duration median and [Q1; Q3] for “Adolescents” were 11,7 [9,6; 15,3] months and 9.3 [4.8; 11.1] months for “Children” subgroup, difference was significant (р=0.043). Most lung functional parameters were in age normal range. Rare cases of functional obstruction were not stable and did not differ in duration between “Children” 7.3 [6.2; 8.8] months and “Adolescents” 8.4 [6.5; 10.4] months.Conclusion. Phenotype markers of future BA exacerbation risk are quite volatile in pediatric patients and young adults. We recommend repeated evaluation of such markers every 12–18 month of observation to decide on asthma controller change. Simultaneous detection of several markers was quite often but did not lead to more severe asthma course in most patients. Longer duration of elevated BMI or peripheral blood eosinophils were typical for patients with more often BA exacerbations.